I do not know that you want to remove that, where exactly is it located on the mobo? Can you give a wider angle (more of the subject)? If it is what I am thinking, I can help but I want to be sure.
well it's located in a "hole", on the edges of the motherboard, all other holes have philips + screws in them but this one has this plastic crap thing, It's a plastic needle with extra plastic on a side, kind of looks like this
and that extra plastic i think makes it hard to remove, but then again I'm pretty careful around the motherboard and if something doesn't come out gently I don't pull it out with all my strength like a gorilla
Take a pair of pliers and squeeze the tab inward. That is a stand-off that is used to attach the mobo to the case. Remove all the screws first and then squeeze to remove the mobo. Otherwise, leave it alone unless you need to remove the mobo.